With prior art arrangements, flat spins were commonly corrected by a parachute deployed from the rear of the aircraft. The parachute created an anti-spin torque by exerting a force, opposite to the spin, through the moment arm extending from the aircraft center of mass to the point of chute attachment. These anti-spin parachutes were frequently installed for use during flight testing of the aircraft, but their installation not only introduced error into the results of those flight tests, but created so many design problems that the chutes were seldom incorporated into operational fighter or commercial planes. The large diameter parachutes and long towlines required stowage compartments in the rear fuselage, and the compartments produced undesirable deviations from the production contours of the aircraft. The large chute forces, in addition, required substantial structural reinforcement of the aircraft to enable it to withstand the high design load of the chute, and such reinforcements altered the mass distribution of the aircraft and its subsequent flight test performance.
Conventional rear deployed anti-spin parachutes created three other problems as well. The parachutes required mechanisms, usually pyrotechnic, to eject the chute beyond the wake of the spinning aircraft. All of these mechanisms required special attention and the explosive devices were potentially unsafe. In addition, even when properly functional, the devices did not prevent the chute from re-entering the wake and such re-entry caused partial or total parachute collapse. Finally, the chutes created so much drag that flight after spin recovery was impossible as long as the chute was in place, and redundant mechanisms to ensure chute release were required.